The present invention relates to a one point ball end mill.
The ball end mill has been used as a cutter for a die milling machine. Conventional such mills are classed into (a) dual-tip solid type, (b) multiple-tip type, and (c) tip row type, which are common in that at least one cutting edge extends from the center to the periphery and cutting edges are arranged symmetrically with respect to the axis. A nicked ball end mill has a cutting edge at the center and cutting edges at the periphery which are arranged on the same milling plane and are regarded as one type of continuous cutting edge.
The conventional ball end mill having continuous cutting edges extending from the center to the periphery suffer from a disadvantage that the cutting performance at the center where the cutting speed is low is extremely poor as compared with that at the periphery. This impedes an efficient operation. In order to overcome such a drawback, the present invention provides a novel ball end mill in which the cutting edge for cutting the center is separated from the cutting edge for cutting the peripheral part.